Bicolored striped-sweat bee (Agapostemon virescens) is your gateway into bee watching. This quintessential backyard bee is found throughout the northeast in backyards and gardens on purple coneflower (Echinacea) and sunflowers (Helianthus), and is known to nest in open areas in turf lawns. Females are distinctive with a metallic green thorax with a black-and-white striped abdomen.
Found from early May through frost, consisting of two activity periods. The first activity period occurs from early May through July and consists of only mated females. The second activity period occurs from August through first frost and consists of both male and female offspring. Mated females from this second activity period overwinter as adults. No nesting occurs during the second period.
Widespread throughout region. Associated with human-occupied areas.
Size ≈ honey bee
Females: unique combination of green thorax and black-and-white-striped abdomen; no other bee looks like this.
Males: more slender than female, with yellow-and-black abdomen. Tricky to distinguish from males of other Agapostemon but notably has dark sternites.
Females are not likely to be mistaken with other metallic green bees in the region.
Males are very similar to males of other Agapostemon, with metallic green head and thorax, black and yellow legs, and a black-and-yellow striped abdomen. Separating A. virescens vs. A. sericeus (the two species most likely to co-occur) requires assessing the color of the sternites. A. virescens males have darker sternites, while A. sericeus males have lighter sternites.
A. virescens nests in a variety of soils, including backyards, parks, and agricultural fields. Nests are communal—many females share a single nest entrance, but lay and provision their own eggs—and nest sites are maintained from year to year. Females take turns guarding nest entrance from intruders, and a green face can often be seen in the nest entrance. A single nest entrance can contain over 30 independently nesting females.
Forages on an incredibly wide range of plants, but with a strong preference for composite Asteraceae, both native and non-native: coneflower (Echinacea), coreopsis (Coreopsis), cup-plant (Silphium), false ox-eye (Heliopsis helianthoides), and thistle (Cirsium) are favorites. Females also collect pollen from wild roses (Rosa) and cherries (Prunus). Males and females nectar on a wide range of plants in the fall, including native wood asters (Symphyotrichum) and non-native mints, e.g. Russian sage (Salvia yangii).
Nomada articulata, Sphecodes dichrous, and S. davisii are likely brood parasites.
Abrams, J. and Eickwort, G.C. 1981. Nest switching and guarding by the communal sweat bee Agapostemon virecens (Hymenoptera: Halictidae) Insectes Sociaux. 28:105-116.
Abrams, J. and Eickwort, G.C. 1980. Biology of the communal sweat bee Agapostemon virescens (Hymenoptera: Halictidae) in New York State. Search. Agriculture. 1-20.
Portman, Z. M., Arduser, M., Lane, I.G., Cariveau, D.P. 2022. A review of the Augochloropsis (Hymenoptera, Halictidae) and keys to the shiny green Halictinae of the midwestern United States. ZooKeys. 1130: 103-152.
Text last updated:
February 22, 2023